[Regrowth patterns of glioma--cases of glioma regrew away from the original tumor].

There have been conflicting opinions regarding the correct volume to be used in radiotherapy fields for malignant glioma. Whereas many clinicians recommend limited fields designed to cover the tumor volume with a margin according to the facts about 90% of recurrent malignant glioma regrew within 2 cm of the original tumor and regrowth away from the original tumor was seen in about 5%. Two cases of malignant glioma regrew away for the original tumor and one case of malignant glioma regrew into the resected site were presented. And the biological characteristics of glioma cells concerning with the invasiveness were discussed.